Effects of anesthetics on early postoperative cognitive outcome and intraoperative cerebral oxygen balance in patients undergoing lung surgery: a randomized clinical trial.

PURPOSE: One-lung ventilation (OLV) may impair cerebral oxygen balance and induce postoperative cognitive dysfunction (POCD). It is unclear whether the type of anesthetic influences the incidence of POCD in patients undergoing OLV. This prospective study compared the incidence of POCD and intraoperative cerebral oxygen desaturation in OLV patients anesthetized with propofol vs sevoflurane during lung surgery. METHODS: There were 148 participants enrolled in this study and randomized equally to either the propofol or the sevoflurane group. Anesthesia was maintained with either propofol or sevoflurane combined in both groups with fentanyl and epidural anesthesia. Regional cerebral oxygen saturation (rSO2), jugular bulb venous oxygen saturation (SjO2), and the incidence of cerebral oxygen desaturation (rSO2 or SjO2 < 50% or rSO2 < 80% of baseline) were measured during anesthesia. Cognitive function was assessed using seven neurocognitive tests two days preoperatively, five days postoperatively (primary outcome), and three months postoperatively. Bivariable and multivariable regression analyses were conducted to identify factors associated with POCD. RESULTS: Rates of POCD did not differ statistically between groups five days postoperatively (propofol, 16/72 patients; sevoflurane, 24/72 patients; RR, 0.67; 95% CI, 0.39 to 1.15; P = 0.14) or three months postoperatively (propofol, 9/60 patients; sevoflurane, 12/58 patients; RR, 0.73; 95% CI, 0.33 to 1.59; P = 0.42). Only three subjects per group showed intraoperative cerebral oxygen desaturation. Multivariable regression analysis revealed older age as an independent predictor of POCD. CONCLUSIONS: No statistically significant difference in the incidence of POCD could be detected between the sevoflurane and propofol anesthesia groups. Postoperative cognitive dysfunction was relatively frequent following OLV in both groups. ( REGISTRATION NUMBER: UMIN 000002826).

RéSUMé: OBJECTIF: La ventilation unipulmonaire (VUP) pourrait avoir un impact négatif sur l'équilibre d'oxygène cérébral et induire une dysfonction cognitive postopératoire (DCPO). Nous ne savons pas si le type d'agent anesthésique influence l'incidence de DCPO chez les patients recevant une VUP. Cette étude prospective a comparé l'incidence de DCPO et de désaturation peropératoire en oxygène cérébral chez les patients sous VUP anesthésiés avec du propofol vs du sévoflurane pendant une chirurgie pulmonaire. MéTHODE: Au total, 148 patients ont participé à cette étude et ont été randomisés en deux groupes égaux à recevoir du propofol ou du sévoflurane. L'anesthésie a été maintenue à l'aide de propofol ou de sévoflurane, et l'agent de choix a été combiné à du fentanyl et à une anesthésie péridurale dans les deux groupes. La saturation en oxygène cérébral régional (rSO2), la saturation en oxygène veineux au bulbe de la veine jugulaire (SjO2) et l'incidence de désaturation en oxygène cérébral (rSO2 ou SjO2 < 50 % ou rSO2 < 80 % par rapport aux valeurs de base) ont été mesurées pendant l'anesthésie. La fonction cognitive a été évaluée à l'aide de sept tests neurocognitifs deux jours avant l'opération, cinq jours après l'opération (critère d'évaluation principal) et trois mois après l'opération. Des analyses de régression bivariée et multivariée ont été réalisées afin d'identifier les facteurs associés à une DCPO. RéSULTATS: D'un point de vue statistique, les taux de DCPO n'étaient pas différents entre les groupes à cinq jours postopératoires (propofol, 16/72 patients; sévoflurane, 24/72 patients; RR, 0,67; IC 95 %, 0,39 à 1,15; P = 0,14) ou à trois mois postopératoires (propofol, 9/60 patients; sévoflurane, 12/58 patients; RR, 0,73, IC 95 %, 0,33 à 1,59; P = 0,42). Seuls trois patients par groupe ont manifesté une désaturation peropératoire en oxygène cérébral. L'analyse de régression multivariée a révélé qu'un âge avancé était un prédicteur indépendant de DCPO. CONCLUSION: Aucune différence significative d'un point de vue statistique n'a été observée en ce qui a trait à l'incidence de DCPO entre les groupes anesthésiés au sévoflurane ou au propofol. La dysfonction cognitive postopératoire était relativement fréquente après une VUP dans les deux groupes. (Numéro d'enregistrement: UMIN 000002826).

[Exposure to 1 % Sevoflurane for 6 Hours Enhances Proliferation of Human Colon Cancer Cells].

BACKGROUND: Sevoflurane is one of the commonly used volatile anesthetics in cancer patients. The protective effect of sevoflurane preconditioning has raised concerns about whether sevoflurane could act advantageously for survival even of cancer cells. Therefore, we investigated the effects of sevoflurane on proliferation in colon cancer cell lines. METHODS: HCT116 and HT29 cells were plated in 96-well plates at a density of 1 x 10(4) cells/well and incubated overnight. On the next day, cells were exposed to 1% or 2% sevoflurane for 6 hr. After 24 hr recovery, we performed MTT assay. The absorbance of the formazan product was measured at a wavelength of 570 nm using 650 nm as the reference. In addition, to investigate the role of adenosine triphosphate-sensitive potassium (K(ATP)) channels, we conducted the same experiment under co-administration of K(ATP) inhibitor, glibenclamide. RESULTS: Only 1% sevoflurane significantly enhanced cell proliferation compared to the control in HCT116 and HT29 cells. Enhanced proliferation by sevoflurane was completely blocked by co-administration with glibenclamide in HCT116 cells. CONCLUSIONS: We had shown that 1% sevoflurane for 6 hr potentially enhances cell proliferation via K(ATP) channels in cancer cells.

Effects of morphine and fentanyl on 5-fluorouracil sensitivity in human colon cancer HCT116 cells.

Opioids are widely used for perioperative pain management in cancer surgery patients. It has been reported that opioids may alter cancer recurrence or progression; however, there are no published reports regarding the effects of opioids on chemotherapy after cancer surgery. Here we investigated the effects of opioids (morphine or fentanyl) on cell proliferation and 5-fluorouracil sensitivity in the human colon cancer cell line, HCT116. First, we exposed cancer cells to the opioid at various concentrations for 6 or 24 h and evaluated cell proliferation using a MTT assay. Next, to simulate the potential postoperative situation in which anticancer drugs are administered after cancer surgery, cancer cells were incubated with the opioid for 6 or 24 h, followed by treatment with 5-fluorouracil for 48 h. Although fentanyl did not affect cell proliferation, morphine exposure for 6 h enhanced the proliferation. However, sensitivity of HCT116 cells to 5-fluorouracil was not altered in all treatment groups. The current study demonstrated that the opioids commonly used during postoperative periods do not affect 5-fluorouracil sensitivity in human colon cancer HCT116 cells.

[Retrospective evaluation of predictors and risks of multiple puncture in central venous catheterization].

BACKGROUND: It has been reported that multiple puncture more than or equal to 3 times is a factor associated with the development of CVC-related complications. The present retrospective study was undertaken to evaluate the predictors and risks of multiple puncture during the insertion of CVC. METHODS: After the IRB approval, 1296 patients who underwent CVC in the operating room were enrolled. Data were collected using CVC report and the medical charts. Multiple puncture was defined as the puncture performed more than or equal to three times during the insertion of CVC. Univariate and multivariate logistic regression analysis were performed to assess the predictors of multiple puncture during the CVC insertion. RESULTS: Univariate analysis revealed that age less than 6 years, complications during insertion and the way to use ultrasound echo were associated with multiple puncture. Multivariate analysis also revealed that age less than 6 years was a significant predictor for multiple puncture (odds ratio 2.08, 95% CI 1.01-4.29). CONCLUSIONS: The results of the study indicate that the age less than 6 years is a significant predictor for multiple puncture during the CVC insertion.

Asymptomatic and symptomatic postoperative visual dysfunction after cardiovascular surgery with cardiopulmonary bypass: a small-sized prospective observational study.

OBJECTIVE: Postoperative visual dysfunction (POVD) after cardiovascular surgery rarely is reported, since it is more likely underdetected and underreported. This study was designed to verify the presence of POVD, including a variety of asymptomatic as well as symptomatic visual dysfunctions after cardiovascular surgery with cardiopulmonary bypass (CPB). DESIGN: A prospective observational study. SETTING: Cardiothoracic surgery in a medical university hospital. PARTICIPANTS: Seventy-one patients undergoing elective cardiovascular surgery with CPB. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: All patients were assessed by a battery of 7 neuro-ophthalmic examinations preoperatively and postoperatively, including fundus, visual field, eye movement, color vision, visual acuity, intraocular pressure, and critical flicker frequency. Patients were considered to have POVD if they had postoperative new abnormal findings of neuro-ophthalmic examinations. One patient was excluded due to a failure of postoperative neuro-ophthalmic examinations. In 16 of 70 patients analyzed in this study, selective cerebral perfusion was required for aortic arch surgery. Of 70 patients, a total of 8 patients (11.4%) had postoperative new abnormal findings in neuro-ophthalmic examinations, including new visual field deficits in 4, reduced visual acuity in 4, and/or increased intraocular pressure in 1 patient. Of these 8 patients, symptomatic POVD was recognized in 1 patient (1.4%) with postoperative visual field deficit and reduced visual acuity. There were no new abnormal findings compared with preoperative results in postoperative funduscopy, eye movement, color vision, and critical flicker frequency. CONCLUSIONS: These results indicated that the asymptomatic as well as symptomatic POVD can develop after cardiovascular surgery with CPB, and their incidence may be relatively high.

Two cases in which the effectiveness of "laryngospasm notch" pressure against laryngospasm was confirmed by imaging examinations.

We report two cases in which development of laryngospasm and release of the spasm immediately after applying pressure in the "laryngospasm notch" was confirmed by ultrasonographic and fiberoptic examinations. A bronchoscopy was planned under propofol sedation using a laryngeal mask airway for a 61-year-old man after subtotal esophagotomy. When a bronchoscope was advanced into the trachea, the vocal cords suddenly closed. Immediately after pressure with the fingertips was applied to the "laryngospasm notch," the vocal cords opened, which was observed through the bronchoscope in real time. A 22-year-old woman presented for emergency caesarean section under general anesthesia. After the completion of the procedures, the patient was not yet following commands but her breathing was steady. Thus, extubation was performed; however, she began to display signs of respiratory stridor. An ultrasonographic examination revealed that the vocal cords were noted to close, which suggested that she was developing laryngospasm. With this diagnosis, pressure at the "laryngospasm notch" was applied. Immediately after this maneuver, the vocal cords opened. We reconfirmed that applying pressure in the "laryngospasm notch" was effective to release laryngospasm. Imaging studies, especially ultrasonographic examination, were useful for making the decision to apply pressure in the "laryngospasm notch."

[Effective use of laryngeal mask airway to stop a supraglottic air leak which prevented adequate ventilation via a tracheostomy in a pediatric patient].

We report a case of ventilation failure due to supraglottic air leakage with the use of uncuffed tracheotomy tube. A 4-year-old girl with 22q11.2 deletion syndrome after tracheotomy due to tracheomalacia developed left caudate bleeding and was admitted urgently. She required mechanical ventilation but suffered from a supraglottic air leakage which prevented adequate ventilation via a tracheostomy site. To stop the supraglottic air leakage, a size 1.5 laryngeal mask airway (LMA) was inserted into the oral pharynx and the cuff was inflated. The supraglottic air leakage was not detected under mandatory mechanical ventilation following seal of the connector of the LMA with a piece of tape. The respiratory condition of the patient improved gradually. The use of an LMA may be useful to stop or significantly decrease the air leak.

[Possible predictors of discontinuation of basal-flow of postoperative patient-controlled analgesia].

BACKGROUND: The purpose of this study was to identify possible predictors of discontinuation of basal-flow of postoperative patient-controlled analgesia. METHODS: We reviewed postoperative pain assessment records by the postoperative pain service team from April 2010 to July 2011 in which surgical patients were provided with intravenous or epidural patient-controlled analgesia (IV-PCA or Epi-PCA). From these data, we extracted cases with discontinuation of basal-flow of PCA, and candidate variables such as patients' characteristics, preoperative and intraoperative variables were assessed. Predictors with significant univariate association (P < 0.20) with the primary outcome were used to construct multivariable logistic regression models. RESULTS: We enrolled 685 patients for IV-PCA and 606 for Epi-PCA and obtained discontinuation groups (105 and 73 cases, respectively) with this cohort data. Results of multivariate analysis showed female, non-laparotomy, low body weight, and non-droperidol as independent risk factors for IV-PCA and low body weight, no-co-existing disease, and gastrointestinal surgery for Epi-PCA. There were no significant differences in pain intensity between discontinuation and non-discontinuation cases. The primary cause of discontinuation was PONV for IV-PCA and hypotension for Epi-PCA, respectively. CONCLUSIONS: We should apply IV-PCA for female slender surgical patients undergoing non-laparotomy with great caution and provide prevention for PON. We should pay attention to incidence of postoperative hypotenion when we administer Epi-PCA to slender gastrointestinal surgical patients without co-existing disease.

[Perioperative quality of life in patients who received "Bokutoh enhanced recovery after surgery" protocol management].

BACKGROUND: After introducing "BOKUTOH enhanced recvery after surgery (ERAS)" protocol for colorectal surgery in our hospital, the hospital stay after surgery was reduced from 10 days to 7. However, the patients' quality of life (QOL) throughout the perioperative period was not quantified. We assessed the QOL of these patients by using QoR-40J and SF-36v2J (Japanese versions of QoR-40 and SF-36v2) questionnaires. METHODS: Twenty-seven colorectal cancer patients undergoing surgery and "BOKUTOH ERAS" protocol management were asked to answer both QoR-40 J and SF-36v2J questionnaires pre- and post-operatively. The scores were evaluated by using Mann-Whitney U-test. RESULTS: From preoperative score (183.5), the scores of QoR-40 J differed significantly on post-operating day (POD) 1 and POD3 (150.9 [15.7] and 168.1 [17.5] points, respectively). Before leaving the hospital (POD6) and after one month from surgery, both QoR40 J and SF-36v2J scores were similar to preoperative ones. CONCLUSIONS: Under "BOKUTOH ERAS" protocol management, patients who had had colorectal surgery were able to recover their QOL within 6 days. Thus, leaving hospital by 7 days after surgery was appropriate to our patients.

Evaluation of the neuroprotective effect of minocycline in a rabbit spinal cord ischemia model.

OBJECTIVE: To investigate whether postischemic administration of minocycline attenuates hind-limb motor dysfunction and gray and white matter injuries after spinal cord ischemia. DESIGN: A prospective, randomized, laboratory investigation. SETTING: Laboratory in university, single institution. PARTICIPANTS: Male New Zealand White rabbits. INTERVENTION: Spinal cord ischemia was induced by an occlusion of the infrarenal aorta for 15 minutes. The groups were administered minocycline 1 hour after reperfusion (M-1; n = 8), minocycline 3 hours after reperfusion (M-3; n = 8), saline 1 hour after reperfusion (control [C]; n = 8), or saline and no occlusion (sham; n = 4). Minocycline was administered intravenously at 10 mg/kg 6 times at 12-hour intervals until 60 hours after the initial administration. MEASUREMENT AND MAIN RESULTS: Hind-limb motor function was assessed using the Tarlov score. For histologic assessments, gray and white matter injuries were evaluated 72 hours after reperfusion using the number of normal neurons and the percentage of areas of vacuolation, respectively. Motor function 72 hours after reperfusion was significantly better in group M-1 than in group C. The number of neurons in the anterior horn was significantly larger in group M-1 than in groups M-3 or C but did not differ significantly between groups M-3 and C. No significant difference was noted in the percentage of areas of vacuolation among the ischemia groups. CONCLUSIONS: Minocycline administration beginning at 1 hour after reperfusion improved hind-limb motor dysfunction and attenuated gray matter injury in a rabbit spinal cord ischemia model.

A case of posterior reversible encephalopathy syndrome after emergence from anesthesia.

Posterior reversible encephalopathy syndrome (PRES) is a relatively new clinical entity characterized by reversible neurological symptoms with findings indicating leukoencephalopathy on imaging studies. Reports of PRES in the field of anesthesiology have been quite limited. A patient with therapeutic anticoagulant developed PRES immediately after emergence from anesthesia, in which her status was initially recognized as delayed recovery from anesthesia with transient hypertension because an emergent head computed tomography (CT) scan was almost normal. Subsequently, magnetic resonance imaging (MRI) was also performed according to a radiologist's recommendation because the CT results showed areas of slightly low attenuation in the frontoparieto-occipital lobes bilaterally, suggesting PRES; otherwise, ischemic events. MRI showed subcortical increased T(2) and fluid-attenuated inversion recovery (FLAIR) intensity in the occipitoparietal regions bilaterally with slight increase in the apparent diffusion coefficient signal on diffusion-weighted imaging, which confirmed a diagnosis of PRES. Gradually, the patient regained consciousness and became responsive with antihypertensive therapy. A prompt and accurate diagnosis of PRES is important to avoid irreversible brain damage, for example, intracranial hemorrhage, especially in a patient receiving anticoagulation therapy.

Anesthetic considerations for masticatory muscle tendon-aponeurosis hyperplasia: a report of 24 cases.

Masticatory muscle tendon-aponeurosis hyperplasia (MMTAH) is a new disease entity characterized by limited mouth opening due to contracture of the masticatory muscles, resulting from hyperplasia of tendons and aponeuroses. In this case series, we report what methods of airway establishment were conclusively chosen after rapid induction of anesthesia. We had 24 consecutive patients with MMTAH who underwent surgical release of its contracture under general anesthesia. Rapid induction of anesthesia with propofol and rocuronium was chosen for all the cases. In 7 cases, intubation using the Macintosh laryngoscopy was attempted; however, 2 of those cases failed to be intubated on the first attempt. Finally, intubation using the McCoy laryngoscopy or fiber-optic intubation was alternatively used in these 2 cases. In 7 cases, the Trachlight was used. In the remaining 10 cases, fiber-optic intubation was used. Limited mouth opening in patients with MMTAH did not improve with muscular relaxation. "Square mandible" has been reported to be one of the clinical features in this disease; however, half of these 24 patients lacked this characteristic, which might affect a definitive diagnosis of this disease for anesthesiologists. An airway problem in patients with MMTAH should not be underestimated, which means that other intubation methods rather than direct laryngoscopy had better be considered.

[Usefulness and problems of pre- and post-operative anesthesia evaluation clinic].

A system of preoperative anesthesia evaluation clinic can provide a chance to evaluate the surgical patients effectively and to obtain an informed consent for anesthesia from the patients with their family. To organize this system effectively, communications with the doctors, nurses and comedical staffs in other departments/ sections are necessary. Postoperative anesthesia evaluation can be performed to gather information about patient satisfaction and postoperative anesthesia-related complications. This information can be used as a feedback to each anesthesiologist to improve anesthetic management. Establishment of anesthesia evaluation clinic can improve the safety and quality of anesthesia as well as efficiency of hospital management.

Fluoroscopically guided epidural blood patch in patients with postdural puncture headache after spinal and epidural anesthesia.

Postdural puncture headache (PDPH) is one of the major complications after spinal and epidural anesthesia. An epidural blood patch (EBP) may be applied when PDPH persists regardless of conservative treatment. We describe the results of management including fluoroscopically guided EBP in a series of patients with moderate to severe PDPH. From January 2007 to December 2009, PDPH developed in 15 of 3,381 patients (0.44%) who received epidural or spinal anesthesia: 5 (0.21%) after general anesthesia combined with epidural anesthesia, 8 (0.81%) after spinal anesthesia, and 2 (3.14%) after combined spinal and epidural anesthesia. Of 15 patients, PDPH was relieved without the EBP in 9 patients and 6 patients required the EBP. EBP was performed under fluoroscopy in a prone position; a 4:1 mixture of autologous blood and contrast medium was injected to cover the site of dural puncture. The success rate of fluoroscopically guided EBP was 100% with a mean blood volume of 7.2 ml. No complications were associated with EBP except for a mild backache. Fluoroscopically guided EBP may be successfully and safely performed to treat persistent PDPH with a relatively small volume of blood for epidural injection.

Amino acid infusions started after development of intraoperative core hypothermia do not affect rewarming but reduce the incidence of postoperative shivering during major abdominal surgery: a randomized trial.

PURPOSE: Previous studies have demonstrated that amino acid infusions exert enhanced thermogenic effects during general anesthesia. This study was conducted to investigate whether amino acid infusions started after development of intraoperative core hypothermia can accelerate rewarming. METHODS: Twenty-two patients scheduled for major abdominal surgery were included in this study. When tympanic temperature reached 35.5°C, patients were randomly assigned to receive amino acids (amino acid group; n = 11) or saline (saline group; n = 11). A continuous infusion of a mixture of 18 amino acids or saline was started at 200 ml h(-1). Tympanic, forearm, and digit temperatures were recorded. Forearm minus fingertip skin-surface temperature gradients (temperature gradient) were calculated. Postoperative shivering was also evaluated. RESULTS: Tympanic membrane temperature and temperature gradient were similar between the two groups at each time point during the study period. Temperature gradient at extubation in the amino acid group was significantly lower than in the saline group although tympanic temperature at extubation was similar between the two groups. Postoperative shivering score was significantly lower in the amino acid group than in the saline group. CONCLUSIONS: Amino acid infusions started after development of intraoperative core hypothermia failed to accelerate rewarming. However, amino acid infusions reduced the incidence of postoperative shivering. Use of amino acid infusions to reduce thermoregulatory vasoconstriction at emergence might contribute to a decrease in the development of postoperative shivering.

Use of a laryngeal mask airway to stop a supraglottic air leak which prevented adequate ventilation via a tracheostomy in a patient with cerebral palsy and pneumonia.

We report an adolescent developing ventilation failure due to supraglottic air leakage with the use of an uncuffed hand-made tracheal tube fit to her tracheobronchial deformity. To eliminate the supraglottic air leakage, a size 2.5 laryngeal mask airway (LMA) was inserted into the oral pharynx. Most of air leakage arose from the LMA. Supraglottic air leakage was not detected under mandatory mechanical ventilation following sealing of the 15-mm connector of the LMA with a piece of tape, and the respiratory condition of the patient gradually improved. The combination of a hand-made Y-shaped tube and the LMA was useful in restoring adequate ventilation. In conditions where air leaks through the glottis during mechanical ventilation interfere with adequate ventilation or the maintenance of airway pressure, the use of an LMA may be adequate to stop or significantly decrease the leak.

Validation of the Japanese version of the quality of recovery score QoR-40.

PURPOSE: The quality of recovery score QoR-40 is a recovery-specific and patient-rated questionnaire to assess the early postoperative health status of patients. However, the Japanese version of the QoR40 has not been established. The aim of this study was to validate the quality of recovery 40 Japanese version (the QoR-40J) according to the methods adopted by the International Quality of Life Assessment (IQOLA) project. METHODS: After obtaining ethics committee approval and consent, 192 general and otological surgical patients were studied. The QoR-40J was used to measure postoperative health status on day 3 and 1 month after surgery. The level of quality of life was also evaluated using a general, health-related quality of life questionnaire (Short-Form Health Survey-36 sub-scales; SF-36), at 1 month after the surgery. Psychometric analysis including the following properties: test-retest reliability, internal consistency, predictive validity, and measurement of responsiveness, was performed to validate the QoR-40J. RESULTS: Test-retest reliability (Spearman's correlation coefficient) and internal consistency (Cronbach's α) of the QoR-40J were 0.887 and 0.91, respectively. A significant relationship was observed between the total QoR-40J score and duration of hospitalization (r = -0.291) and between the global QoR-40J score and postoperative scores of the SF-36 sub-scales (physical function, ρ = 0.287; vital score, ρ = 0.349). The standardized mean of the QoR-40J, a measurement of responsiveness, was 0.70. CONCLUSION: The results of the psychometric analysis indicated that the QoR-40J has characteristics of acceptable validity, reliability, and responsiveness in clinical practice in Japan. The QoR-40J may aid in evaluating the quality of recovery after surgery or the quality of methods of anesthesia.

Assessment of intraoperative motor evoked potentials for predicting postoperative paraplegia in thoracic and thoracoabdominal aortic aneurysm repair.

PURPOSE: Monitoring motor evoked potentials (MEPs) has been recognized as a highly reliable method to detect intraoperative spinal cord ischemia (SCI) in aortic repair. However, the data regarding the sensitivity and specificity of MEPs for predicting postoperative paraplegia are limited. We retrospectively assessed the value of intraoperative MEP amplitudes for predicting postoperative paraplegia. METHODS: The medical records of 44 patients were reviewed. A train-of-five stimulation was delivered to C3-C4, and MEPs were recorded from the abductor pollicis brevis and the tibialis anterior muscles. The cutoff point for detecting SCI was set at 75% decrease of the baseline MEP. Receiver operating characteristic curves were applied at various cutoff points. RESULTS: Three patients (6.8%) had postoperative paraplegia. The minimum MEP during surgery had 100% sensitivity and 64.9% specificity in predicting paraplegia, and the MEP at the end of surgery had 66.7% sensitivity and 78.0% specificity in predicting paraplegia: only 1 patient, who had borderline paraplegia (right monoparesis), showed a false-negative result. Receiver operating characteristic curves indicated that adequate cutoff points for the minimum MEP during surgery and for the MEP amplitude at the end of surgery were a 75-90% decrease and a 64-75% decrease of the baseline MEP, respectively. CONCLUSION: Monitoring MEPs had relatively high sensitivity and acceptable specificity, with the cutoff point set at 75% decrease of the baseline MEP, for predicting paraplegia and paraparesis. Because of the small sample in our study, further investigations would be necessary to investigate an adequate cutoff point that could predict postoperative paraplegia.

Difficult passage of the endotracheal tube and massive nasal bleeding during awake nasal fiberoptic intubation in a patient with airway obstruction caused by neck hematoma--a case report.

A 60 yr-old male underwent anterior cervical fusion under general anesthesia. Neck swelling was observed at the next morning. Subsequently, emergent CT scanning was performed, which revealed a retropharyngeal hematoma narrowing the upper airway and right anterior neck hematoma significantly deviating the trachea and larynx. Nasal intubation was attempted but difficult passage of the endotracheal tube counteracted this procedure. Immediately, massive nasal bleeding occurred, which worsened the situation. Subsequently, oral fiberoptic intubation with the aid of McCoy type laryngoscope was tried and intubation was barely established. The patient was submitted to emergent evacuation of the hematoma. Reevaluation of the preoperative CT images showed the nasal cavity narrowing because of widespread nasal mucosal swelling. It is necessary to anticipate that nasal mucosal swelling and bleeding tendency due to impairment of venous drainage can exist in such a case.

Current Status of Clinical Engineer Anesthesia Assistants and Their Effect on Labor Task Shifting in Japan: A Prospective Observational Study in a Single Institute.

INTRODUCTION: Anesthesiologists are in short supply across the world, resulting in perpetually long working hours. To reduce the burden on anesthesiologists, tasks that can be performed by non-physicians must be shifted to other medical staff. In hospitals, clinical engineers can work as anesthesia assistants and perform some of the duties of anesthesiologists. This study aimed to evaluate the effect of task shift performed by clinical engineer anesthesia assistants (CEAAs). METHODS: This was a 1-month prospective observational study that included 33 anesthesiologists (11 fellows and 22 certified anesthesiologists) and 11 CEAAs. The total activity and anesthesia times were extracted from the attendance record as indices of the anesthesiologists' work status. The CEAAs recorded the duration of work performed on behalf of the anesthesiologists as task shift time. The task shift rate was evaluated as follows: task shift time/(task shift time + total activity time) and task shift time/(task shift time) + (total anesthesia time). RESULTS: The study period consisted of 19 weekdays. The average daily activity time of the anesthesiologists was 10.1 h, and the average anesthesia time was 8.5 h. The CEAAs performed a total of 546.8 h of task shift. The defined task shift rate was 20.1% when the total activity time was the denominator and 23.1% when the anesthesia time was the denominator. CONCLUSIONS: CEAAs might be effective in reducing the working hours of anesthesiologists through task shift. Their taking over a portion of the anesthesiologists' duties may allow the anesthesiologists to work more efficiently.